1.) Obviously you are going to do it. You shouldn't have any excuse not to have beautiful backgound. PR has some gorgeous beaches.
2.) You can't really complain about a 1000 deposit for a 2500 lens. They will have to repair/replace it if you end up breaking or losing it. The place with the 15.00 damage waiver...read the fine print on that one, I am not sure how they stay in business. I assume that doesnt include loss. If it does, I'll buy it off ya.
3.) If you do plan to buy any new glass, consider some alternatives, Sigmas 70-200 2.8, or Tamrons, 17-55 2.8, less than half the price of Canons counterpart.
4.) Kiss your wifes ass because your going to have to ignore her all night if you want to do a good job. aka - no nookie.
5.) Not sure the last time you flew...but luggage isn't cheap to check anymore, so pack your gear conservatively, if you don't want it to arrive in more pieces than it arrived, make it your carry on.
6.) Practice, practice, practice, stay loose, and have fun
7.) Do a great job, they could be poweful shots for a portfolio...just dont promise like results unless you are a destination wedding photog...dreaming of that day myself!